1. Field of the Invention
The present invention relates to an adjustable wrench wherein the sliding jaw is lockingly engaged in one of a plurality of predetermined positions, the locking engagement being noticeable by a user without visual verification.
2. Description of the Related Art
Adjustable wrenches, often referred to as crescent wrenches, are a highly used and conveniently utilized tool. The reason for their convenient usage is the ability to vary the grasping dimensions of the wrench to meet specific needs. Traditionally, the spacing of the grasping faces of the wrench were adjusted by a worm gear disposed within a head portion of the wrench, the adjustment being visually made and finer adjustments necessarily waiting until positioning over the item to be grasped. Unfortunately, however, the adjustment process was often difficult and cumbersome especially when the wrench was utilized in hard to reach places, and had to be opened to release an item and readjusted to grasp an item of similar dimension. Fortunately, most screws, bolts, and the like are dimensioned in standard English or metric units which enables individual socket wrenches or permanently sized wrenches to be utilized. This sizing, however, does not benefit the use of an adjustable wrench because of the need to manually adjust its dimensions by visualization and comparison. As a result, it would be highly beneficial to provide an adjustable wrench which could be easily utilized with the standard dimensions.
In the past, there have been various adjustable wrenches which have attempted to allow locked engagement of the dimension or to facilitate visualization of the dimensions. Such adaptations include adaptations of pipe wrenches such as that disclosed in the reference to Cox, U.S. Pat. No. 4,580,468 and Baxter, U.S. Pat. No. 3,662,630, as well as adaptations of crescent type adjustable wrenches such as those disclosed in O'Quin, U.S. Pat. No. 3,376,767, Bonkowski, U.S. Pat. No. 2,850,932, Parnet, U.S. Pat. No. 2,369,072, Hose, U.S. Pat. No. 1,397,214, and McGraw, U.S. Pat. No. 4,326,436. These designs, however, while providing graded scales and providing for the locked engagement of the grasping jaws in a desired location, generally require complicated maneuvering and positioning, are not facilitated for use with only one hand, and are not readily adapted to identify locked engagement when used in difficult to reach locations wherein the spacing cannot be visualized and wherein due to the use of gloves or other circumstances, the locking in place cannot be easily felt. Still another important difficulty with regard to the recited variations, a difficulty which has minimized the widespread use of locking adjustable wrenches and maintain the need for an effective adjustable wrench, is the complicated manufacturing adaptation which must be undertaken in order to forge a wrench including the locking means. Adaptation of existing molds as well as the substantially increased labor required to put together a locking adjustable wrench of the type recited can significantly increase the cost of manufacturing, and accordingly buying a wrench, and can be more susceptible to such difficulties by a user who is not familiar with the functioning of the locking means. Additionally, the reference to Green, U.S. Pat. No. 2,722,150, utilizes a spring and ballbearing system to facilitate adjustability of the wrench jaws. The self-locking jaw wrench of Green, however, is adapted to directly engage the worm gear of the adjustable wrench and accordingly after prolonged use, may result in slippage making the set scale imprecise. Further, the wrench of Green as disclosed is not adapted to urge the ballbearing into a recess of sufficient depth so as to make a substantially audible sound, thereby further signalling positioning of the jaws at a predetermined spacing. Accordingly, there is still a need for an adjustable wrench such as that of the present invention wherein manufacturing adaptations are minimal, the dimensions will be significantly accurate as locking is determined directly between the stationary head portion and the sliding jaw rather than the sliding jaw and the rotating worm gear which is susceptible to slippage, and which enables tactile as well as audible identification by a user that the sliding jaw has locked into place at a desired predetermined distance.